Every week 3 members of a cooking club total their food cost and determine the mean amount that each person should contribute. This week, the mean contribution per member is $30. A fourth person who wants to join the cooking club buys $20 worth of food. What is the mean contribution for this week if the fourth person joins the cooking club.
3 members have a mean of $30 and thus a total amount of $90. If a fourth person contributes $20 to the total then the answer would be $110/4 people which is $27.50 per person.